Condensed Statement of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Cash flows from operating activities
Net loss	$ (11,273)	$ (9,956)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	510	380
Loss on disposal of property and equipment		80
Stock-based compensation	839	211
Non-cash loss on extinguishment of debt	185
Change in fair value of redeemable convertible preferred stock warrant liability		(21)
Change in fair value of derivative liability		(265)
Non-cash interest expense	119	783
Compensation expense related to vesting of common stock to GLOBALFOUNDRIES	716	1,442
Changes in operating assets and liabilities:
Accounts receivable	(460)	(821)
Amounts due from related parties	(64)	62
Inventory	(1,584)	404
Prepaid expenses and other current assets	48	(507)
Other assets	(11)	3
Accounts payable	51	967
Accrued liabilities	100	292
Amounts due to related parties	(229)	2,197
Deferred income on shipments to distributors	(237)	203
Deferred revenue		(104)
Net cash used in operating activities	(11,290)	(4,650)
Cash flows from investing activities
Purchases of property and equipment	(1,704)	(427)
Net cash used in investing activities	(1,704)	(427)
Cash flows from financing activities
Proceeds from convertible promissory notes-related party		5,000
Proceeds from debt	12,000	1,500
Payments on debt	(8,356)	(355)
Payments of debt issuance costs	(49)	(15)
Payments on capital lease obligation	(7)	(129)
Payments of deferred offering costs		(618)
Proceeds from exercise of stock options and purchase of shares in employee stock purchase plan	855	29
Net cash provided by financing activities	4,443	5,412
Net (decrease) increase in cash and cash equivalents	(8,551)	335
Cash and cash equivalents at beginning of period	29,727	2,307
Cash and cash equivalents at end of period	21,176	2,642
Supplementary cash flow information:
Interest paid	288	401
Non-cash investing and financing activities:
Purchase of property and equipment in accounts payable and amounts due to related parties	$ 560
Purchase of property and equipment under capital lease obligations		34
Deferred offering costs recorded in accounts payable and accrued liabilities		$ 942